OCT Bests FFR Guidance in Optimizing PCI: FORZA

Batya Swift Yasgur MA, LSW

October 10, 2019

Optical coherence tomography (OCT) guidance is superior to fractional flow reserve (FFR) guidance in assessing and intervening in angiographically intermediate coronary lesions (AICL) and optimizing percutaneous coronary interventions (PCIs), a new study suggests.

Investigators randomized 350 patients with AICL to receive either FFR or OCT, with a primary end point of major adverse cardiac events (MACE) or significant angina at 13 months. They also compared the cost of each intervention.

OCT guidance was found to be superior to FFR guidance, with a lower occurrence of the composite of MACE and significant angina. However, FFR guidance was associated with a higher rate of medical management and lower costs.

Francesco Burzotta (Source: Fredy Perojo/Medscape)

"We designed a single-center prospective randomized trial comparing the use of OCT — the new cutting-edge intracoronary imaging technique — with FFR, the gold standard, in 250 patients with angiographically intermediate coronary lesions," colead author Francesco Burzotta, MD, PhD, Institute of Cardiology, Fondazione Policlinico Universitario A. Gemelli IRCCS, Università Cattolica del Sacro Couere, Rome, told theheart.org | Medscape Cardiology.

The results were presented at Transcatheter Cardiovascular Therapeutics (TCT) 2019 and simultaneously published online September 29 in JACC: Cardiovascular Interventions.

"OCT prompted more initial PCIs and carried out more costs [but] the results at 13 months showed a reduction of the primary combined end point of MACE or significant residual angina," he continued.

"The latter observations, reported for the first [time] at TCT 2019, are original and prompt for further research in the field," he said.

Emerging Strategy

"The best treatment of patients with angiographically intermediate coronary lesions is a daily challenge worldwide," Burzotta observed.

OCT is an emerging strategy to optimize PCI result, but its use to decide whether to treat coronary lesions is unknown, and no study directly compared so far FFR and OCT before the FFR or OCT Guidance to Revascularize Intermediate Coronary Stenosis Using Angioplasty (FORZA) trial," he said.

The FORZA trial involved 350 patients with stable ischemic disease or stabilized (i.e., after a previously treated culprit lesion) acute coronary syndrome (ACS) and evidence of at least one AICL who were randomized 1:1 to receive either FFR or OCT guidance (n = 176 and n = 174, respectively) for PCI performance and PCI optimization (in those requiring revascularization).

Cardiovascular risk factors (i.e., diabetes and chronic kidney disease) were "highly prevalent" in 35.4% and 17.7% of cases, respectively, although most patients were stable, with preserved left ventricular ejection fraction (LVEF).

AICL was defined as "a coronary lesion with a visually estimated percentage diameter stenosis ranging from 30% to 80% in the [nondistal segment] of a major epicardial vessel."

Patients were required to have one of three conditions: single vessel disease with AICL; multivessel disease with AICL only; or multivessel disease with at least one AICL and previously treated angiographic critical stenoses.

Multivessel disease was "common," with a mean investigated lesion per patient of 1.27 in both groups.

Other baseline characteristics were comparable between the 2 groups, except that patients in the OCT group had a significantly higher prevalence of previous MI, whereas patients in the FFR group had a higher prevalence of left anterior descending artery involvement.

The researchers set different requirements for the performance of PCI in each group. PCI was performed in the FFR group if FFR was 0.80 or less.

Criteria for performing PCI in the OCT group are listed below.

  • Area stenosis of at least 75%

  • Area stenosis of 50% to 75% with minimal lumen area less than 2.5 mm2

  • Area stenosis of 50% to 75% with plaque rupture

Follow-up was set at 13 months, at which point angina (evaluated by the Seattle Angina Questionnaire [SAQ]), MACE, and costs were assessed.

"Significant angina" was defined as SAQ frequency score below 90 and, together with MACE, formed a composite primary end point.

"Cutting Edge"

Of the lesions in the FFR and OCT groups, 29.3% and 50.7%, respectively were managed with PCI, translating into a "statistically higher rate of patients referred to initial medical management with FFR."

At 13 months, 14.8% of patients in the FFR group and 8.0% of patients in the OCT group experienced the primary end point of MACE or significant angina (= .048).

The authors comment that this result "was driven by a not statistically significant lower occurrence of all primary end point components."

However, in multivariate analysis, randomization to OCT was "confirmed to independently predict the primary end point" (adjusted hazard ratio, 0.40; CI, 0.19 - 085; = .018).

The authors highlight the finding that target vessel failure occurred less frequently in the OCT than in the FFR group (2.3% vs 7.4%; = .027).

The rate of medically managed patients over 13 months was significantly higher with FFR than with OCT (62.5% vs 44.8%; < .001), and the mean estimated total cost per patient up to 13 months was significantly lower with FFR than with OCT (€ 2577 [95% CI, 2038 - 3470] vs € 3750 [95% CI, 2734 - 4503]; < .001).

"Among different techniques, OCT represents a cutting-edge imaging modality since it offers, as compared with intravascular ultrasound, improved image quality," the authors comment.

Preliminary Findings

Commenting on the study for theheart.org | Medscape Cardiology, Ajay J. Kirtane, MD, SM, associate professor of medicine, Columbia University Medical Center, New York City, called the study design that compared technologies "novel," although the findings are still "preliminary," given that it is a single-center study.

"The biggest challenge for me in interpreting these data and bringing them into practice is that there are two components for each technology — diagnostic and interventional — and it is not clear to me to what extent this study can parse out which affected the outcome," said Kirtane, who is also the chief academic officer, Center for Interventional Vascular Therapy and the director of the NYP/Columbia Cardiac Catheterization Laboratories.

"It is well known that physiologic testing is best at deciding whether not to treat and that imaging modalities are optimized to help the treatment procedure, so because this study combined both the diagnostic and optimization components of the procedure together, I can't tell you whether the approach proposed is the best one or whether one should use physiology to decide what to treat and OCT to decide how to treat, which is what I do in my clinical practice," he explained.

"I use physiology to decide what to treat and imaging to decide how to treat," stated Kirtane, who moderated the session at which the FORZA trial was presented and was not involved with the research.

Burzotta agreed that a single-center study such as theirs "cannot change clinical practice; nevertheless, the finding of our study are interesting and call for further evaluations of OCT in clinical practice."

He noted that his group is "looking at long-term follow-up of patients enrolled in the FORZA trial" to assess if adverse events "will continue to split between patients randomized to FFR vs OCT."

Moreover, "we want to assess if the benefit of OCT vs FFR was due to better timing of treatment by PCI or to better outcomes in patients who underwent PCI with OCT optimization."

The FORZA trial was funded by academic grants (Bando Linea D. 1 – Università Cattolica del Sacro Cuore, Roma). Burzotta received speaker's fees from Abbott, Medtronic, and Abiomed. The other authors' disclosures are listed in the published study. Kirtane reports institutional funding to Columbia University and/or Cardiovascular Research Foundation from Medtronic, Boston Scientific, Abbott Vascular, Abiomed, CSI, Philips, and ReCor Medical.

Transcatheter Cardiovascular Therapeutics 2019: Late-breaking trials 4. Presented September 29, 2019.

JACC Cardiovasc Interv. Published online September 29, 2019. Abstract

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